diff --git a/maximum-depth-of-binary-tree-104/Cargo.toml b/maximum-depth-of-binary-tree-104/Cargo.toml
new file mode 100644
index 0000000..a9ad825
--- /dev/null
+++ b/maximum-depth-of-binary-tree-104/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "maximum-depth-of-binary-tree-104"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
diff --git a/maximum-depth-of-binary-tree-104/src/main.rs b/maximum-depth-of-binary-tree-104/src/main.rs
new file mode 100644
index 0000000..a6d5854
--- /dev/null
+++ b/maximum-depth-of-binary-tree-104/src/main.rs
@@ -0,0 +1,40 @@
+// Definition for a binary tree node.
+struct Solution {}
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct TreeNode {
+    pub val: i32,
+    pub left: Option<Rc<RefCell<TreeNode>>>,
+    pub right: Option<Rc<RefCell<TreeNode>>>,
+}
+
+impl TreeNode {
+    #[inline]
+    pub fn new(val: i32) -> Self {
+        TreeNode {
+            val,
+            left: None,
+            right: None,
+        }
+    }
+}
+
+use std::cell::RefCell;
+use std::rc::Rc;
+impl Solution {
+    pub fn max_depth(root: Option<Rc<RefCell<TreeNode>>>) -> i32 {
+        match root {
+            None => 0,
+            Some(node) => {
+                1 + std::cmp::max(
+                    Self::max_depth(node.borrow().left.clone()),
+                    Self::max_depth(node.borrow().right.clone()),
+                )
+            }
+        }
+    }
+}
+
+fn main() {
+    println!("Hello, world!");
+}